Calorifiers ????

RutlandMike

RutlandMike

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Just a quickie. I need to replace my calorifier which is donkeys years old and leaking. Looking over replacements, any single coil cylinders labelled 'marine' or called 'calorifiers' seem to cost on average 3 times as much as a normal domestic single coil hot water cylinder. Two questions:
1. Are marine calorifiers substantially different to domestic cylinders and
2. will a domestic coil tolerate coolant pressures from a couple of 235hp engines?

Any opinions greatly appreciated as always!
 
these people seem to have units at sensible prices.

http://www.copperform.co.uk/specialized_units/boat_cylinder/index.htm
The working pressure is up to 5 bar and relief valves normally come in at 3.5. The design is the same as domestic ones, but they can add additional output and input fittings.

I've put in a Jabsco accumulator to even out any pressure surges.

It's not so much the pressure from the engines' water pump system, but the flow rate from two big engines. You may have to put flow restrictor valves in (which is also useful for isolating the calorifier)
 
Agree with sarabande, 'domestic' are fine, though I've personally never seen one small enough - for our boat anyway! Certainly you don't need to get a stainless steel version as a normal copper one will last many, many years. Ours , for example, is now in it's 24th years and perfect.

Oh Lord, watch it spring a leak now! /forums/images/graemlins/frown.gif /forums/images/graemlins/smile.gif
 
Domestic cylinders are designed to run with an open vent. The pressure from the boat's domestic water pump will burst the seams on a cylinder that is unvented. Engine circulating water has no affect on the cylinder as it is contained in the coil.
You can use a sealed system cylinder but these ar not much cheaper than the proper marine calorifier. This is one of the few instances where the real thing is the proper thing!
 
[ QUOTE ]
Domestic cylinders are designed to run with an open vent. The pressure from the boat's domestic water pump will burst the seams on a cylinder that is unvented. Engine circulating water has no affect on the cylinder as it is contained in the coil.
You can use a sealed system cylinder but these ar not much cheaper than the proper marine calorifier. This is one of the few instances where the real thing is the proper thing!

[/ QUOTE ]

That's exactly why I put the word 'domestic' in quotes!! In the context I was referring more to a copper calorifier which most peeps I've spoken to/advised seem to refer to as domestic.

Done lots of central heating installation work etc so agree with you re the domestic characteristics.

As I normally post when this question is asked, I've never seen a domestic calorifieir small enough to fit in a boat (well, the size of mine 10m) so have always assumed it's a no-no anyway!

As I say, I do not believe, from my own experience and that of many friends, that a stainless steel unit is necessary.
 
<<< As I say, I do not believe, from my own experience and that of many friends, that a stainless steel unit is necessary. >>>

I agree. The original one fitted to my boat by Sadlers was about 25 litres, perhaps a little more, and entirely of copper, including the coil. It had a standard fitting for an immersion heater but none was ever fitted. It was about 17 years old when I replaced it, perfectly OK except that I couldn't remove the immersion heater blank and the insulation was very battered.
 
I was planning on fitting an expansion vessel or at least a pressure release valve that would discharge to the bilges - would the seams still blow regardless? I'm fortunate in that there's a lot of room under my floors which would accomodate 120ltr cylinder - vertical or horizontal - which is about what we'd need a day liveaboard (showers, washing up, handbasins etc). Thanks all the above chaps - keep it coming!
 
[ QUOTE ]
Domestic cylinders are designed to run with an open vent. The pressure from the boat's domestic water pump will burst the seams on a cylinder that is unvented. Engine circulating water has no affect on the cylinder as it is contained in the coil.
You can use a sealed system cylinder but these ar not much cheaper than the proper marine calorifier. This is one of the few instances where the real thing is the proper thing!

[/ QUOTE ]


It doesnt matter if its for open vent, some open vent systems in tall buildings have high static pressures. What matters is the safe working pressure which will be labeled on it.
 
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